javascript效果积累帖（广告图片切换）

Question

淘宝NNT
<script type=text/javascript>
<!--
//var nPic = new Array(),nPiclink=new Array(),nPicTit=new Array(),preloadedimages=new Array();
var nPic = new Array(),nPiclink=new Array(),preloadedimages=new Array();
var nPicNum=0;
nPic[0]="../nntcn_image/pic/shua1.gif";
nPiclink[0]="#";

preloadedimages[1]=new Image();
preloadedimages[1].src=nPic[0];//Modify2008-03-28 Author:xinghai.li
nPic[1]="../nntcn_image/pic/gg200809.gif";
nPiclink[1]="#";
preloadedimages[2]=new Image();
preloadedimages[2].src=nPic[1];//Modify2008-03-28 Author:xinghai.li
nPic[2]="../nntcn_image/pic/gg3.gif";
nPiclink[2]="#";
preloadedimages[3]=new Image();
preloadedimages[3].src=nPic[2];//Modify2008-03-28 Author:xinghai.li
nPic[3]="../nntcn_image/pic/gg2.gif";
nPiclink[3]="#"; function setTransition(){
if(document.all) {
document.getElementById('nPicRotator').filters.revealTrans.Transition=23;
document.getElementById('nPicRotator').filters.revealTrans.apply();
}
}
function playTransition(){
if(document.all){
//alert("nPicRotator" + document.getElementById('nPicRotator'));
document.getElementById('nPicRotator').filters.revealTrans.play();
}
}
function nextAd(){
if(nPicNum < nPic.length-1){
nPicNum++;
} else {
nPicNum=0;
}
midWay();
theTimer=setTimeout("nextAd()",4000);
}
function midWay(){
setTransition();
document.getElementById('nPicRotator').src=nPic[nPicNum];
document.getElementById('nPicRotatorA').href=nPiclink[nPicNum];

playTransition();
}
theTimer=setTimeout("nextAd()",4000);
//-->
</script>